Dissipationless Spin Current Generation in Kitaev's Chiral Spin Liquid

Abstract

$\alpha$-RuCl${}_3$ is a promising candidate material for the Kitaev spin liquid state where the half quantization of the thermal Hall effect, suggesting a topological character, has been observed. However, its relation to the existence of chiral Majorana fermions, which is predicted from the theory of the Kitaev model, is still under debate. Here we propose a more direct signature of a chiral Majorana edge mode which emerges in a universal scaling of the Drude weight of the edge spin Seebeck effect in the Kitaev model. Moreover, the absence of backscatterings in the chiral edge mode results in the generation of a dissipationless spin current in spite of an extremely short spin correlation length close to a lattice constant in the bulk. This result is not only experimentally observable, but also opens a way towards spintronics application of Kitaev materials. In contrast to magnetically ordered systems, a Kitaev spin liquid state is stable even in the atomic scale and makes it possible to fabricate a highly integrated device with substantial efficiency to generate a spin current. This proposal for using $\alpha$-RuCl${}_3$ as a nano-scale device will pioneer Kitaev spintronics.

8 pages, 4 figures

References in corpus (14)

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Cited by in corpus (8)

• Spin Seebeck Effect: Sensitive Probe for Elementary Excitation, Spin Correlation, Transport, Magnetic Order, and Domains in Solids
• Non-local spin correlation as a signature of Ising anyons trapped in vacancies of the Kitaev spin liquid
• Scattering phenomena for spin transport in Kitaev spin liquid
• Field-driven spatiotemporal manipulation of Majorana zero modes in a Kitaev spin liquid
• Interedge spin resonance in the Kitaev quantum spin liquid
• Spin Seebeck Effect as a Probe for Majorana Fermions in Kitaev Spin Liquids
• Nonreciprocal heat transport in the Kitaev chiral spin liquid
• Fidelity of the Kitaev honeycomb model under a quench